1. Field of the Invention
The present invention relates to umbrellas. More specifically, the present invention relates to an asymmetric umbrella having an off-center shaft.
2. Description of the Prior Art
Umbrellas conventionally comprise of a center shaft from which a plurality of ribs of equal length are pivotally attached. The ribs extend radially outwards forming a symmetrical frame supporting a canopy. The disadvantage of a conventional umbrella having a center shaft is that it divides the canopy space, forcing the user to be displaced to the perimeter of the canopy. Due to this displacement, conventional umbrellas provide inadequate shelter, exposing the users' side and back to the elements. Moreover, the unused canopy space, particularly of larger umbrellas, makes walking difficult on busy sidewalks.
Asymmetrical umbrellas are known. Asymmetrical umbrellas provide an off-center shaft, thereby allowing the user to stand beneath the center of the umbrella canopy, thereby providing greater protection from the elements. For example, U.S. Pat. Nos. 4,474,201 and 4,474,200 to Kida disclose umbrellas having an oval canopy and an asymmetrically disposed shaft. However, the asymmetrical umbrellas disclosed by the Kida references have a canopy that is functionally inferior to conventional umbrella canopies. Specifically, the Kida umbrella canopies are loosely and unsightly bunched about the frame when the frame is in the closed position. Patent WO9944458, to Goudarzi discloses an asymmetrical umbrella having ribs of equal length when the umbrella is in the folded position. The Goudarzi design is functionally inferior to conventional umbrellas because when the umbrella is in the folded position several of the distal ribs of the long main ribs fold upwards in an inverted fold, while several short main ribs point downwards. The inverted fold is structurally weak and is inadequate to fully extend the umbrella canopy when in the open position. Moreover, when the umbrella of Goudarzi is in the closed position, the upwardly folding long distal ribs are exposed. The exposed upwardly folding long distal ribs are unsightly and are subject to damage.
U.S. Pat. No. 5,505,221 to Gao discloses an asymmetrical umbrella having telescoping deployment arms of varying lengths. The Gao umbrella is also inferior to conventional umbrellas. Telescoping deployment arms weaken the overall structure of the umbrella, as telescoping components are easily subject to bending and breaking, thereby rendering the umbrella inoperable. Moreover, the umbrella of Gao has distal ribs of graded length to offset the shaft and maintain a circular canopy shape when opened. Thus, when the Gao umbrella is in the closed position, the distal ribs terminate unevenly, resulting in an awkward appearance.
Asymmetrical umbrellas known in the art have been awkward in usability and stowage. The disadvantages are most evident when the umbrellas are closed, displaying uneven distal rib lengths, some of which point up as well as down, or telescoping and slidable ribs which are not only costly to construct and easily broken, but create unsightly bunching of the canopy.
Thus, a need exists for an improved asymmetric umbrella having distal ends that point in the same direction when the canopy is collapsed. A need further exists for an asymmetric umbrella having rib assemblies of substantially uniform length when the canopy is collapsed.